When visual programming is applied to design, it results in a parametric modelling approach that we refer to as Visual Dataflow Modelling (VDM). This paper reviews existing VDM environments and identifies key issues that result in dataflow graphs with high complexity. In order to explore how these issues could be overcome, a new VDM environment is being developed, called Vidamo. For any given parametric modelling task, Vidamo aims to support a style of VDM where the complexity of the dataflow graph remains commensurate with the complexity of the task. An initial experiment is conducted in which the existing environments and the proposed Vidamo environment are used to complete the same parametric modelling task. The results indicate that the dataflow graphs created using Vidamo are much smaller and less complex.